1. Field of the Invention
This invention relates to an advanced driving system and more particularly to a system and process for the automatic calculation of the coefficient of a slope about to be ascended by a motor vehicle and an associated device.
Generally speaking, the domain of the invention is that of advanced driving assistance systems. This domain includes for example the known devices for detecting obstacles, night vision devices, devices for warning the driver that he is approaching a bend, devices for optimizing the use of headlamps in accordance with driving conditions etc. Such devices all make use of different types of sensors. The solutions proposed are essentially based on technologies such as radar, lidar and ultrasound and they are able in particular to detect close obstacles at low speed; these solutions are also based on processes involving the use of devices such as cameras.
2. Description of the Related Art
Sensors of the radar and lidar type, which are typically used for the application of remote detection, such as the ACC system (Autonomous Cruise Control) for example, provide direct information on the position and sometimes the 2D speed of objects located directly in a road scene. This information allows the different objects that are present to be classified and enables to assign to them useful information such as their position and sometimes their speed with current coordinates in two dimensions, relative to the vehicle fitted with the sensor in question and relative to a fixed point of reference if the position of the vehicle is clearly established in this reference.
However, such sensors do not provide a wide range of vision and their angular position is never very precise. Moreover, these sensors do not provide any information on the environment of the roadway, such as the position of the vehicle within its traffic lane, the number of traffic lanes, the trajectory of the road, the classification of obstacles or the recognition of infrastructural elements such as road signs and the like.
Consequently, numerous driving assistance devices use cameras, usually working together with image processing algorithms dedicated to these specific functions. The object of the present invention belongs to such driving assistance devices.
The problem that the present invention aims to solve is as follows: at present there is no means by which the functional characteristics of the motor vehicle can be determined by the arrival of a vehicle at the start of a slope. However, numerous characteristics could be improved.
For example, as shown in FIG. 1, with regard to the lighting of the roadway, the appearance of a slope affects the range of the beam of the headlamps generated by the vehicle. This effect can be disturbing for the driver. On this figure, it can be seen that when a vehicle approaches a slope 100, the range of this beam reduces as the vehicle approaches the slope. For example, in the example given, a headlamp beam capable of covering 80 meters when the vehicle is traveling on a flat road, will only cover 40 meters as shown by a first straight line 101, representing the upper limit of the beam produced by the vehicle. In terms of the slope 100, to restore the range of 80 meters, as shown by a second straight line 102, it is necessary to modify the direction of the headlamps creating the beam in question.
Another example of characteristics that could be improved lies in the flow of fuel to the engine. For example, to maintain a constant speed when a slope is being ascended, the engine will inevitably consume more fuel that when it is traveling on a flat road. If the ascent of the slope is not anticipated by adjusting the flow of fuel to the engine, the speed of the vehicle will fall as the slope commences, which detracts from driving comfort.
Consequently, the fact that a slope is not anticipated is likely to lead to a reduction in driving comfort.